1. Field of the Invention
The invention generally relates to cooling and ventilating systems for pressure suits and more particularly to an improved cooling and ventilating garment particularly suited for use in removing metabolic heat, waste gases and water vapor from an hermetically sealed outer suit, hereinafter referred to as a spacesuit.
2. Description of the Prior Art
The prior art includes teachings of numerous approaches to the problem of achieving removal of metabolic heat and gaseous wastes generated by a wearer of an hermetically sealed spacesuit. For example, it has been common practice to sew into undergarments for spacesuits cooling circuits including flexible liquid circulating tubes and liquid circulation patches, as well as to employ ventilation systems of numerous configurations for removing waste gases and water vapor from the suit.
In the Apollo/Skylab programs, a cooling unit made of elastomeric material having attached thereto a network of flexible tubes for accommodating circulation of water was employed. The head of the astronaut, hereinafter referred to as a wearer, was not covered and all ventilation gases were fed to the helmet and collected in a return vent system attached to the suit. The cooling system required that a high flow rate of 240 pounds per hour, with temperatures as low as 42.degree. F, be established through the suit in order to remove most of the metabolic heat generated by the wearer. It has been found that the gas circulation systems heretofore employed generally tend to be ineffective in removing perspiration, since the gas becomes substantially saturated with moisture as it exits the helmet of the spacesuit and flows out over the body of the wearer. Moreover, since the entire quantity of gas must be delivered to the suit through small ducts, relatively large pressure drops are experienced when employing such systems. Finally, the tubes heretofore employed in venting spacesuits must be loosely attached to the suit with considerable excess being provided in order to accommodate motion in the region of the joints of the spacesuit. Use of excessive lengths of tubing, of course, tends to increase bulk and is attended by a liklihood that the tubing will experience a collapse, particularly near the mobility joints of the spacesuit.
It is therefore the general purpose of the instant invention to provide in combination with an hermetically sealed spacesuit an improved cooling garment of reduced bulk and complexity, particularly suited for use in removing metabolic heat, waste gases and water vapor from the suit with increased efficiency.